不同精粗比饲粮中添加凝结芽孢杆菌对绵羊羔羊瘤胃发酵和免疫功能的影响

Effects of Adding Bacillus coagulans into Diets with Different Concentrate to Forage Ratios on Rumen Fermentation and Immune Function of Lambs

本试验旨在研究不同精粗比饲粮中添加凝结芽孢杆菌(BC)对绵羊羔羊生长性能、瘤胃发酵和免疫功能的影响。试验采用2×2双因子完全随机设计,2个因素分别为精粗比[40∶60(低精料)、70∶30(高精料)]和BC[不添加和添加1.0×10^(10)CFU/kg BC]。选取48只体重相近的4月龄杜泊×小尾寒羊F1代公羔,随机分为4个组,分别饲喂低精料饲粮(LD组)、添加BC的低精料饲粮(LD+BC组)、高精料饲粮(HD组)、添加BC的高精料饲粮(HD+BC组),每组12只。预试期10 d,正试期60 d。结果显示:1)24只饲喂高精料饲粮的羔羊瘤胃内pH,氨态氮、乙酸、异丁酸浓度以及乙丙比值显著低于24只饲喂低精料饲粮的羔羊(P<0.05),丙酸、戊酸和总挥发性脂肪酸浓度显著高于24只饲喂低精料饲粮的羔羊(P<0.05);24只饲喂添加BC饲粮的羔羊瘤胃内丙酸浓度显著高于24只饲喂未添加BC饲粮的羔羊(P<0.05)。饲粮精粗比和BC之间在瘤胃发酵参数上不存在显著的交互作用(P>0.05)。2)24只饲喂高精料饲粮的羔羊瘤胃内淀粉酶和蛋白酶活性显著高于24只饲喂低精料饲粮的羔羊(P<0.05),木聚糖酶活性显著低于24只饲喂低精料饲粮的羔羊(P<0.05);24只饲喂高精料饲粮的羔羊瘤胃内的总菌、栖瘤胃普雷沃氏菌、嗜淀粉瘤胃杆菌数量显著高于24只饲喂低精料饲粮的羔羊(P<0.05),黄色瘤胃球菌、产琥珀酸丝状杆菌、溶纤维丁酸弧菌和原虫数量显著低于24只饲喂低精料饲粮的羔羊(P<0.05)。24只饲喂添加BC饲粮的羔羊瘤胃内淀粉酶活性显著高于24只饲喂未添加BC饲粮的羔羊(P<0.05)。24只饲喂添加BC饲粮的羔羊瘤胃内嗜淀粉瘤胃杆菌、栖瘤胃普雷沃氏菌和溶纤维丁酸弧菌数量显著高于24只饲喂未添加BC饲粮的羔羊(P<0.05)。饲粮精粗比和BC之间在瘤胃微生物酶活性和功能微生物数量上不存在显著的交互作用(P>0.05)。3)24只饲喂高精料饲粮的羔羊血清中免疫球蛋白G(IgG)含量显著低于24只饲喂低精料饲粮的羔羊(P<0.05)。24只饲喂添加BC饲粮的羔羊血清中白细胞介素-4(IL⁃4)含量显著高于24只饲喂未添加BC饲粮的羔羊(P<0.05)。饲粮精粗比和BC在血清中IL⁃4含量上存在显著的交互作用(P<0.05)。综上所述,在不同精粗比饲粮中添加BC均可以促进瘤胃发酵,有效提高羔羊对饲粮的消化吸收,同时还可以提高机体炎症应答水平,进而促进羔羊健康生长,且在高精料饲喂条件下添加BC效果更好。因此,BC可以作为一种新型的益生菌制剂应用于羔羊生产中,且在精粗比为70∶30的高精料饲粮中添加效果更优。

The aim of this experiment was to investigate the effects of adding Bacillus coagulans(BC)into diets with different concentrate to forage ratios on rumen fermentation and immune function of lambs.A 2×2 twofactorial completely randomized design was used in the experiment,with different ratio of concentrate to forage(40∶60 of lowconcentrate diet or 70∶30 of highconcentrate diet)and BC(adding 0 or 1.0×1010 CFU/kg BC)as two factors.Fortyeight Duper×smalltail Han sheep F1 male lambs with similar body weight and at the age of 4 months were selected and randomly divided into 4 groups with 12 lambs in each group.Lambs in LD,LD+BC,HD and HD+BC groups were fed lowconcentrate diet,lowconcentrate plus BC diet,highconcentrate diet and highconcentrate plus BC diet,respectively.the pretest period was 10 days,and the trial period was 60 days.The results showed as follows:1)the pH,the concentrations of ammonia nitrogen,acetate,isovalerate and acetate/propionate ratio in the rumen of 24 lambs fed highconcentrate diet were significantly lower than those of 24 lambs fed lowconcentrate diet(P<0.05),and the concentrations of propionate,valerate and total volatile fatty acids were significantly higher than those of 24 lambs fed lowconcentrate diet(P<0.05);the concentration of propionate in the rumen of 24 lambs fed adding BC diet was significantly higher than that of 24 lambs fed no BC diet(P<0.05).There were no significant interactions between dietary concentrate to forage ratio and BC on rumen fermentation parameters(P>0.05).2)The activities of amylase and protease in the rumen of 24 lambs fed highconcentrate diet were significantly higher than those of 24 lambs fed lowconcentrate diet(P<0.05),and the activity of xylanase was significantly lower than that of 24 lambs fed lowconcentrate diet(P<0.05).The counts of total bacteria,P.ruminicola and R.amylophilus in the rumen of 24 lambs fed highconcentrate diet were significantly higher than those of 24 lambs fed lowconcentrate diet(P<0.05),and the counts of R.flavefaciens,F.succinicogenes,B.fibrisolven and protozoa were significantly lower than those of 24 lambs fed lowconcentrate diet(P<0.05).The rumen amylase activity of 24 lambs fed adding BC diet was significantly higher than that of 24 lambs fed no BC diet(P<0.05).The counts of total bacteria,R.amylophilus and P.ruminicola and B.fibrisolvens in the rumen of 24 lambs fed adding BC diet were significantly higher than those of 24 lambs fed no BC diet(P<0.05).There were no significant interactions between dietary concentrate to forage ratio and BC in rumen microbial enzyme activities and functional microorganism counts of lambs(P>0.05).3)The serum immunoglobulin G(IgG)content of 24 lambs fed highconcentrate diet was significantly lower than that of 24 lambs fed lowconcentrate diet(P<0.05).The serum interleukin4(IL4)content of 24 lambs fed adding BC diet was significantly higher than that of 24 lambs fed no BC diet(P<0.05).There was a significant interaction between dietary concentrate to forage ratio and BC on serum IL4 content of lambs(P<0.05).In conclusion,adding BC into diets with different concentrate to forage ratios can promote rumen fermentation,effectively improve the digestion and absorption of the diet,and also improve the inflammatory response level of the body,thus promoting the healthy growth of lambs,and the effect of BC supplementation is better under highconcentrate feeding conditions.Therefore,BC can be used as a new probiotic preparation in lamb production,and the effect of adding BC to highconcentrate diet with concentrate to forage ratio of 70∶30 is better.